The reaction between bromobenzene and palladium(0) complexes leading to a palladium(II) complex containing bromide and phenyl ligands is studied computationally with DFT methods. Three different mechanisms are considered: concerted, nucleophilic substitution and radical. A systematic analysis is carried out on the effect on each of these mechanisms of a number of variables: the identity of the phosphine (PF3, PH3, PMe3 or PPh3), the nature of the solvent (vacuum, tetrahydrofuran, dimethylformamide or water) and the number of phosphine ligands (mono- or bis-phosphine). The concerted and nucleophilic substitution mechanisms are competitive in many cases, the identity of the preferred one depending on a combination of factors. Additional calculations with bromomethane, bromoethylene and bromoethane are carried out in selected cases for further clarification.
The diverse mechanisms for the oxidative addition of C–Br bonds to Pd(PR3) and Pd(PR3)2 complexes
Dalton Trans. 2019, 48, 16242-16248, DOI: 10.1039/C9DT03155C.